This invention relates to an isokinetic exercise device and more particularly to an isokinetic device utilizing a speed control assembly for presenting a selectable number of operable speeds to the user.
As set forth in an embodiment of U.S. Pat. No. 3,929,331 entitled "Exercise Device" issued Dec. 30, 1975 which is hereby incorporated into this specification, an assembly is provided for use as an operator-energized, torque-responsive exercise device. This assembly includes a pair of mutually rotatable members having operator handles thereon with the members being mounted in a facing relationship with spreading means therebetween. The spreading means, in the form of spherical ball bearings, are positioned between paired arcuate raceways located in the facing services of the rotatable members. The raceways are aligned such that relative rotation of the members causes the ball bearings to move along their raceways until captivation therebetween so as to axially displace or spread apart the members. This spreading apart operates an associated brake assembly which in turn retards the rotation of the manually operated members. The retardation is presented as a resistance to the operator through the handles in an amount proportional to the force applied there to which provides an isokinetic exercise corresponding to the strength capability of the operator.
These devices have been limited in their range of use as there has been no means to selectably adjust the speeds at which the exercise device could be operated. This absence of a speed adjustment limited the effective user of a particular exercise device only to those users initially having the strength to operate the device at the inherently designed single speed.
The present invention provides for an exercise device which utilizes a speed control assembly allowing the user to select a speed of operation by adjusting the axial distance between the paired arcuate raceways prior to the start of the exercise movement. This selectable axial distance affects the position of the ball bearings along the raceways at captivation, the paired raceways being particularly designed to change the angle of contact between the captivated balls and the raceways. In turn, this angle of contact controls the intensity of forces delivered to the associated brake assembly upon operation of the exercise device and the ultimate resistance presented to the operator. Accordingly, a range of speeds of operation of the device are provided which allows a single exercise device to be used by operators of diverse strengths without the need to change the critical design parameters incorporated therein.
It is therefore a general object of this invention to provide an isokinetic exercise device having a speed control assembly incorporated therein which allows a user to selectably set the speed at which the device can be effectively operated.
Another object of this invention is to provide an isokinetic exercise device, as aforesaid, which can be operated by a wide range of users of various strength capabilities.
Still another object of this invention is to provide an isokinetic exercise device, as aforesaid, which is rugged in construction so as to withstand the forces acting thereon during performance of the exercise.
A further object of this invention is to provide an isokinetic exercise device, as aforesaid, which has a plurality of selectable ranges of resistance designed therein which can be selectably offered to the user.
A particular object of this invention is to provide an isokinetic exercise device, as aforesaid, utilizing ball bearings captivated in paired arcuate raceways to provide a driving connection among the linked elements of the device.
Another particular object of this invention is to provide an isokinetic exercise device, as aforesaid, having means therein to regulate the location of the ball bearings at captivation, in order to control the mechanics of the driving connection offered thereby.
Still another particular object of this invention is to provide an isokinetic exercise device utilizing ball bearings captivated in paired arcuate raceways, as aforesaid, the raceways particularly designed to change the contact angle of the ball bearings therein to control the mechanics of the driving connection offered thereby.
Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, an embodiment of this invention.